-@node Basic polyphony
-@unnumberedsubsubsec Basic polyphony
-
-@cindex polyphony
-
-The easiest way to enter fragments with more than one voice on a
-staff is to enter each voice as a sequence (with @code{@{...@}}),
-and combine them simultaneously, separating the voices with
-@code{\\}
-
-@funindex \\
-
-@lilypond[quote,verbatim,fragment]
-\new Staff \relative c' {
- c16 d e f
- <<
- { g4 f e | d2 e2 } \\
- { r8 e4 d c8 ~ | c b16 a b8 g ~ g2 } \\
- { s2. | s4 b4 c2 }
- >>
-}
-@end lilypond
-
-@cindex layers
-
-The separator causes @internalsref{Voice}
-contexts@footnote{Polyphonic voices are sometimes
-called @q{layers} in other notation packages} to be instantiated.
-They bear the names @code{"1"}, @code{"2"}, etc. In each of these
-contexts, vertical direction of slurs, stems, etc., is set
-appropriately.
-
-These voices are all separate from the voice that contains the
-notes just outside the @code{<< \\ >>} construct. This should be
-noted when making changes at the voice level. This also means
-that slurs and ties cannot go into or out of a @code{<< \\ >>}
-construct. Conversely, parallel voices from separate @code{<< \\
->>} constructs on the same staff are the same voice. Here is the
-same example, with different noteheads and colors for each voice.
-Note that the change to the note-head style in the main voice does
-not affect the inside of the @code{<< \\ >>} constructs. Also,
-the change to the second voice in the first @code{<< \\ >>}
-construct is effective in the second @code{<< \\ >>}, and the
-voice is tied across the two constructs.
-
-@cindex note heads, styles
-
-@lilypond[quote,verbatim,fragment]
-\new Staff \relative c' {
- \override NoteHead #'style = #'cross
- \override NoteHead #'color = #red
- c16 d e f
- <<
- { g4 f e } \\
- { \override NoteHead #'style = #'triangle
- \override NoteHead #'color = #blue
- r8 e4 d c8 ~ }
- >> |
- <<
- { d2 e2 } \\
- { c8 b16 a b8 g ~ g2 } \\
- { \override NoteHead #'style = #'slash
- \override NoteHead #'color = #green
- s4 b4 c2 }
- >>
-}
-@end lilypond
-
-Polyphony does not change the relationship of notes within a
-@code{\relative @{ @}} block. Each note is calculated relative to
-the note immediately preceding it.
-
-@example
-\relative @{ noteA << noteB \\ noteC >> noteD @}
-@end example
-
-@code{noteC} is relative to @code{noteB}, not @code{noteA};
-@code{noteD} is relative to @code{noteC}, not @code{noteB} or
-@code{noteA}.
-
-
-@node Explicitly instantiating voices
-@unnumberedsubsubsec Explicitly instantiating voices
-
-@internalsref{Voice} contexts can also be instantiated manually
-inside a @code{<< >>} block to create polyphonic music, using
-@code{\voiceOne}, up to @code{\voiceFour} to assign stem
-directions and a horizontal shift for each part.
-
-Specifically,
-@example
-<< \upper \\ \lower >>
-@end example
-
-@noindent
-is equivalent to
-
-@example
-<<
- \new Voice = "1" @{ \voiceOne \upper @}
- \new Voice = "2" @{ \voiceTwo \lower @}
->>
-@end example
-
-The @code{\voiceXXX} commands set the direction of stems, slurs,
-ties, articulations, text annotations, augmentation dots of dotted
-notes, and fingerings. @code{\voiceOne} and @code{\voiceThree}
-make these objects point upwards, while @code{\voiceTwo} and
-@code{\voiceFour} make them point downwards. The command
-@code{\oneVoice} will revert back to the normal setting.
-
-An expression that appears directly inside a @code{<< >>} belongs
-to the main voice. This is useful when extra voices appear while
-the main voice is playing. Here is a more correct rendition of
-the example from the previous section. The crossed colored
-noteheads demonstrate that the main melody is now in a single
-voice context.
-
-@lilypond[quote,ragged-right,verbatim]
-\new Staff \relative c' {
- \override NoteHead #'style = #'cross
- \override NoteHead #'color = #red
- c16 d e f
- \voiceOne
- <<
- { g4 f e | d2 e2 }
- \new Voice="1" { \voiceTwo
- r8 e4 d c8 ~ | c8 b16 a b8 g ~ g2
- \oneVoice
- }
- \new Voice { \voiceThree
- s2. | s4 b4 c2
- \oneVoice
- }
- >>
- \oneVoice
-}
-@end lilypond
-
-The correct definition of the voices allows the melody to be
-slurred.
-
-@lilypond[quote,ragged-right,verbatim]
-\new Staff \relative c' {
- c16^( d e f
- \voiceOne
- <<
- { g4 f e | d2 e2) }
- \context Voice="1" { \voiceTwo
- r8 e4 d c8 ~ | c8 b16 a b8 g ~ g2
- \oneVoice
- }
- \new Voice { \voiceThree
- s2. s4 b4 c2
- \oneVoice
- }
- >>
- \oneVoice
-}
-@end lilypond
-
-Avoiding the @code{\\} separator also allows nesting polyphony
-constructs, which in some case might be a more natural way to
-typeset the music.
-
-@lilypond[quote,ragged-right,verbatim]
-\new Staff \relative c' {
- c16^( d e f
- \voiceOne
- <<
- { g4 f e | d2 e2) }
- \context Voice="1" { \voiceTwo
- r8 e4 d c8 ~ |
- <<
- {c8 b16 a b8 g ~ g2}
- \new Voice { \voiceThree
- s4 b4 c2
- \oneVoice
- }
- >>
- \oneVoice
- }
- >>
- \oneVoice
-}
-@end lilypond
-
-In some instances of complex polyphonic music, you may need
-additional voices to avoid collisions between notes. Additional
-voices are added by defining an identifier, as shown below:
-
-@lilypond[quote,verbatim,ragged-right,relative=2]
-voiceFive = #(context-spec-music (make-voice-props-set 4) 'Voice)
-
-\relative c''' <<
- { \voiceOne g4 ~ \stemDown g32[ f( es d c b a b64 )g] } \\
- { \voiceThree b4} \\
- { \voiceFive d,} \\
- { \voiceTwo g,}
->>
-@end lilypond
-
-
-@node Collision Resolution
-@unnumberedsubsubsec Collision Resolution